Abstract: A communication apparatus has a receiver and a decoder. The receiver receives a control signal including first downlink control information and second downlink control information, and receives decoding area information that indicates whether the extended Physical Downlink Control Channel (PDCCH) should be decoded for each of a plurality of terminal apparatuses. The decoder decodes each of a plurality of first mapping candidates in the PDCCH area or decodes each of the plurality of first mapping candidates in the PDCCH area and each of the plurality of second mapping candidates in the extended PDCCH. A number of the second mapping candidates included in the user-specific search space equals to or is more than a number of the first mapping candidates included in the common search space.

Abstract: Provided are a base station, whereby the erroneous detection of control information can be reduced, thereby preventing the degradation of the system throughput. A base station maps a downstream allocation control information unit, which is addressed to a terminal, to a first resource region, which can be used for any of a downstream control channel region and a downstream data channel region, or to a second resource region, which can be used only for the downstream control channel, so as to transmit the downstream allocation control information unit. In the base station, a control unit establishes a scale of the PDCCH region, and a transmission region establishing unit establishes, on the basis of a scale value established by the control unit, a mapping region to which the DCI is mapped within the R-PDCCH region and the PDCCH region.

Abstract: A communication apparatus has a receiver and a decoder. The receiver receives a control signal including first downlink control information and second downlink control information, and receives decoding area information that indicates whether the extended Physical Downlink Control Channel (PDCCH) should be decoded for each of a plurality of terminal apparatuses. The decoder decodes each of a plurality of first mapping candidates in the PDCCH area or decodes each of the plurality of first mapping candidates in the PDCCH area and each of the plurality of second mapping candidates in the extended PDCCH. A number of the second mapping candidates included in the user-specific search space equals to or is more than a number of the first mapping candidates included in the common search space.

Abstract: A process for growing a crystal of a nitride semiconductor in which after the step of mounting a substrate (12) in a reaction tube (11), the step of feeding a first material gas containing a Group 3 element onto the substrate in the reaction tube and the step of feeding a second material gas containing elemental nitrogen onto the substrate in the reaction tube are carried out alternately to deposit a nitride semiconductor crystal directly on the substrate. The number of moles of the elemental nitrogen contained in the second material gas has a ratio of 200 or more to the number of moles of the Group 3 element in the first material gas.

Abstract: Disclosed is a bipolar semiconductor device which is capable of reducing the surface state density of a bipolar transistor and increasing the current gain of the transistor, thereby improving the transistor performance. A bipolar semiconductor device (100) has a surface protective film (30) on the surface of a semiconductor element. The surface protective film is composed of a thermal oxide film (31) formed on the surface of the semiconductor element, and a deposited oxide film (32) formed on the thermal oxide film. The deposited oxide film contains at least one of hydrogen element and nitrogen element in an amount of not less than 1018 cm?3.

Abstract: A bipolar semiconductor device includes a collector region that is an n-type low-resistance layer formed in one surface of a semiconductor crystal substrate, an n-type first high-resistance region on the collector region, a p-type base region on the first high-resistance region, an n-type low-resistance emitter region that is formed in another surface of the semiconductor crystal substrate, an n-type second high-resistance region between the emitter region and the base region so as to contact the emitter region, an n-type recombination suppressing region around the second high-resistance region so as to adjoin the second high-resistance region, and a p-type low-resistance base contact region which is provided so as to adjoin the recombination suppressing region, and which contacts the base region. Each of doping concentrations of the second high-resistance region and the recombination suppressing region is equal to or lower than 1×1017 cm?3.

Abstract: A process for growing a crystal of a nitride semiconductor in which after the step of mounting a substrate (12) in a reaction tube (11), the step of feeding a first material gas containing a Group 3 element onto the substrate in the reaction tube and the step of feeding a second material gas containing elemental nitrogen onto the substrate in the reaction tube are carried out alternately to deposit a nitride semiconductor crystal directly on the substrate. The number of moles of the elemental nitrogen contained in the second material gas has a ratio of 200 or more to the number of moles of the Group 3 element in the first material gas.